Abstract:

The invention provides methods of making provisional and long-term dental
restorations, particularly dental veneers, implants, crowns and bridges.
A shell or restoration form made of polymerizable material having good
dimensional shape-stability in its uncured condition is used to make the
dental restoration. A polymerizable material is introduced into the
cavity of the shell form. The outer shell and injected polymerizable
material are polymerized and bond together to form a hardened crown
structure. In one embodiment, the restoration can be fabricated
indirectly by a dental laboratory. In another version, a dental
practitioner can make the restoration chairside for a patient in a dental
office.

Claims:

1. A method of making a dental restoration on a dental model of .a
patient's dental anatomy, comprising the steps of: a) providing a
non-polymerized shell form comprising a first polymerizable material, the
shell having a cavity therein so that it may be mounted over the dental
model; b) introducing a heated second polymerizable material into the
cavity of the shell form; c) placing the shell form containing the second
polymerizable material over a targeted area on the dental model that will
receive the restoration; d) allowing the shell and second polymerizable
material to cool and form a dimensionally, shape-stable uncured
restoration on the model; d) irradiating the shell and second
polymerizable material with light so they cure and form a hardened
restoration; and e) removing the fully cured restoration from the model.

2. The method of claim 1, wherein the shell form is placed over the
dental model prior to introducing the second polymerizable material into
the cavity of the shell form.

3. The method of claim 2, wherein the shell form is trimmed and adjusted
while it is positioned on the model.

4. The method of claim 1, wherein the first and second polymerizable
materials each comprise a polymerizable acrylic compound and
polymerization initiation system, capable of being activated by light or
heat, for polymerizing the materials.

5. The method of claim 4, wherein the first and second polymerizable
materials further comprise particulate filler.

6. The method of claim 4, wherein the first and second polymerizable
materials have the same composition.

7. The method of claim 4, wherein the first and second polymerizable
materials have different compositions.

8. The method of claim 4, wherein the polymerizable acrylic compound is a
semi-crystalline material.

9. The method of claim 4, wherein the polymerization initiation system
comprises a photoactive agent.

10. The method of claim 5, wherein the filler material is selected from
the group of inorganic and organic materials and mixtures thereof.

11. The method of claim 1, wherein the shell form and second
polymerizable material have shades resembling enamel shades of natural
teeth.

12. The method of claim 1, wherein the shell form and second
polymerizable material have shades resembling dentin shades of natural
teeth.

13. The method of claim 1, wherein the shell form and second
polymerizable material have shades resembling enamel and dentin shades of
natural teeth.

14. The method of claim 1, wherein the restoration includes a supporting
substructure.

15. The method of claim 14, wherein the substructure is a metallic
material.

16. The method of claim 14, wherein the substructure is a ceramic
material.

17. The method of claim 14, wherein the substructure is a
fiber-reinforced composite.

18. A method of making a dental restoration on a prepared tooth,
comprising the steps of: a) providing a non-polymerized shell form
comprising a first polymerizable material, the shell having a cavity
therein so that it may be mounted over the prepared tooth; b) introducing
a heated second polymerizable material into the cavity of the shell form;
c) placing the shell form containing the second polymerizable material
over a prepared tooth in a mouth of a patient; d) irradiating the shell
form and second polymerizable material with light to form a partially
cured restoration inside of the mouth; e) removing the partially-cured
restoration from the tooth and irradiating the restoration with light
outside of the mouth to form a fully cured restoration.

19. The method of claim 18, wherein the shell form is placed over the
prepared tooth prior to introducing the polymerizable material into the
shell form cavity so that it can be trimmed and adjusted.

20. The method of claim 18, wherein the patient bites down upon the
restoration prior to forming the partially cured restoration so that the
fit of the restoration can be checked.

21. The method of claim 18, wherein the first and second polymerizable
materials each comprises polymerizable acrylic compound and
polymerization initiation system, capable of being activated by light or
heat, for polymerizing the materials.

23. The method of claim 22, wherein the filler material is selected from
inorganic and organic materials and mixtures thereof.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent
Application 60/848,117 having a filing date of Sep. 29, 2006, the entire
contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates generally to methods and kits for
making provisional and long-term dental crowns, bridges, inlays, onlays,
veneers, implants, and other dental restorations. A shell or restoration
form made of polymerizable material having good dimensional
shape-stability is used to make the dental restoration. In one method,
the restoration can be fabricated indirectly by a dental laboratory and
sent to a dentist for placing in the mouth of a patient. In another
version, the dentist can make the restoration in the dental office
directly.

[0004] 2. Brief Description of the Related Art

[0005] Dental restorations, such as crowns and bridges, are used to
restore or replace lost tooth structure, teeth, or oral tissue.
Provisional (or temporary) restorations are intended to be used for a
relatively short time. For example, a dentist will often use a
provisional crown, until a permanent crown is ready to be placed in the
mouth of a patient. Following one conventional procedure, the dentist
makes the provisional crown for the patient at the dental office and a
dental laboratory makes the permanent crown. The dentist mounts the
provisional crown to protect the tooth while the permanent crown is being
made. Later, the dentist removes the provisional crown and replaces it
with the permanent crown.

[0006] In one conventional method, the provisional crown is made using a
prefabricated shell made of a metal such as aluminum, stainless steel,
anodized gold, or polycarbonate. Because human teeth come in different
sizes and shapes, many different shell forms must be available. The shell
may be trimmed and shaped to fit properly over the prepared tooth
structure. The shell cavity is typically filled with a polymerizable
resinous material that may contain filler particulate. The shell
containing the resinous material along with a temporary adhesive or
cement is placed on the prepared tooth. The shell is irradiated with
ultraviolet or visible light to cure the polymerizable resinous material
and dental cement. Thus, the provisional crown is affixed to the tooth
structure. Ideally, the shell form is shaped to achieve optimum margins,
interproximal contacts, and occlusion. However, one problem with using
prefabricated metal shell restorations is that they can be difficult to
grind and shape. On the other hand, if polycarbonate shells are used,
there can be problems with grinding the shell's occlusal surface--this
may expose the filled resin and cause delamination and staining. Also,
the bond strength between the shell and resin can be low even when a
primer coating is used. Moreover, it is difficult to make adjustments to
the rigid polycarbonate shell so as to obtain the desired bite surface.
Another problem with using prefabricated metal shells is they may provide
an esthetically non-pleasing appearance, and it can be difficult to find
a shell that fits properly. One attempt to solve this problem involves
providing many different shell forms having different sizes and shapes
(for example, shells for molars and bicuspids). However, making so many
different shell forms available to the dentist is expensive and
time-consuming. As described further below, the polymerizable shell forms
of this invention solve many of the problems associated with using
conventional shell forms.

[0007] In recent years, techniques for making provisional crowns using
prefabricated shells made of polymeric materials have been developed. For
example, Rosellini, U.S. Pat. Nos. 5,192,207 and 5,332,390 disclose a
method for making a permanent crown. After the tooth that will receive
the crown has been prepared, a transparent shell tooth form is filled
with a light-setting resin. The filled shell is placed on the prepared
tooth and a light source (typically ultraviolet) is directed at thereon.
This sets the light-setting resin and bonds the resin to the shell form.
Preferably, the shell form is made from the same light-setting resin used
to fill the shell so that there is good bonding therebetween. Thereafter,
the tooth form is shaped and polished in situ to form the permanent
crown.

[0008] Updyke, U.S. Pat. No. 5,775,913 discloses a method that allows a
dentist to "cap" a tooth in a single office visit. The preferred material
for making the crown shell or cap is known as ARTGLASS (Herarus Kulzer),
a photopolymerizable multifunctional methacrylate monomer resin filled
with different sized glass particles. The shell is prepared by molding
and light-curing the ARTGLASS material. Then the cap is filled with an
uncured, resinous material, preferably CHARISMA (Herarus Kulzer), a
photopolymerizable multifunctional methacrylate monomer resin filled with
glass particles. The cap is placed over the prepared tooth and the
patient bites down. The dentist uses a curing light to cure the interior
resin so that it bonds with the tooth and becomes integral with the cap.

[0009] Harlan, U.S. Pat. No. 6,935,862 discloses a method for making a
crown, short-span bridge, or other dental prosthesis in a single office
visit. The method involves placing a prefabricated shell that can be made
from a polymerizable material, for example CRISTOBAL, a polyacrylic glass
composite (Dentsply) over a prepared tooth. The shell is trimmed to
achieve desired seating on the tooth and optimal occlusion. The shell is
then removed from the tooth, and the tooth's prepared surface is painted
with a separating medium. An interior surface of the shell is painted
with a bonding agent, and an uncured composite material is added to the
shell's cavity. Next the shell is positioned over the tooth, and the
composite material in the cavity of the shell is partially light cured in
situ. The shell is removed from the tooth and uncured composite material
is added to the external surface of the shell. The added composite is
then fully light cured, and the shell is affixed to the tooth.

[0010] Kvitrud et al., US Patent Application Publication US 2005/0042577
discloses dental crown forms having a handle attached to the crown form
at a location removed from the base of the crown form. The crown form is
filled with a hardenable material shortly before placing the crown form
over the prepared tooth. The handle can be vented so that excess material
can pass during placement of the crown form. One advantage with this
crown form according to the published application is that the handle
provides improved accessibility during placement of the crown form on the
tooth. The published application notes that if the hardenable dental
material is of a type that can retain its desired shape before hardening
and after release from the interior surfaces of the dental crown form,
the practitioner may remove the dental crown form before hardening the
dental material.

[0011] In another instance, Chilibeck, U.S. Pat. No. 6,884,073 discloses a
method for making temporary and semi-permanent crowns using a crown shell
or form that is filled with resin. The crown form and resin are made from
photopolymerizable materials, preferably comprising Bis-GMA. The crown
form, having an incompletely polymerized layer is filled with resin. The
crown is then fitted onto the tooth stub. The incompletely polymerized
layer of the crown and injected resin are photopolymerized or
autopolymerized in the mouth of the patient. The incompletely polymerized
layer polymerizes with the resin as the resin is being polymerized.

[0012] As discussed above, there are numerous methods for making
conventional provisional (temporary) dental restorations such as crowns
and short-span bridges. A patient wears the provisional crown for a
relatively short period of time, that is, until a permanent crown is
made. Today, provisional crowns and bridges typically are used by a
patient for a period of about three to six months. In general, such
provisional restorations are effective, but there is a need in the dental
field for restorations that can be used for longer periods. One object of
the present invention is to provide dental restorations that can be used
short-term (for example, a period of about one to twelve months) and
long-term (for example, greater than twelve months).

[0013] The present invention provides methods for making such dental
restorations using shell forms. A dental practitioner can use the
resulting dental restoration as a provisional expecting that it will
remain in the patient's mouth for a time period of about 1 to about 12
months. On the other hand, if the dental practitioner wishes to use the
dental restoration as a long-term product, expecting that it will remain
in the patient's mouth for a period of time longer than about 12 months,
he or she can do so. The dental restorations of this invention can be
used as either provisional or long-term dental products because of their
advantageous properties. Particularly, the restorations are strong and
durable and do not break or fracture easily. Because of their mechanical
strength, the restorations can withstand hard occlusion forces. In
addition, the restorations have pleasing aesthetics matching the shade of
natural teeth. Moreover, the restorations have good margins and contacts,
providing the patient with comfort while promoting dental health. The
restoration covers and supports the tooth structure sufficiently so that
it protects the tooth's pulpal portion.

[0014] Another object of the present invention is to provide a method that
a dental laboratory can use to easily make dental crowns, bridges,
inlays, onlays, veneers, implants, and other dental restorations having
good mechanical strength, aesthetics, and occlusal fit.

[0015] Another object of this invention is to provide a method that a
dental practitioner can easily use to design and fabricate the crown,
bridge, or other dental restoration "chairside." This would help make the
crown manufacturing and fitting process less time-consuming and costly.
The dentist would be able to prepare and mount the crown on the patient's
tooth in a single office visit. In such a method, the dentist should be
able to check the crown and easily make adjustments, if needed, to
achieve optimum comfort and fit. Another object of this invention is to
provide a material which can be shaped and contoured easily to prepare a
crown having good comfort and fit.

[0016] These and other objects, features, and advantages of this invention
are evident from the following description and illustrated embodiments.

SUMMARY OF THE INVENTION

[0017] This invention provides methods for making provisional and
long-term dental crowns, bridges, inlays, onlays, veneers, implants, and
other dental restorations using polymerizable shell forms. In one
version, a dental laboratory can make the restoration. This method
involves providing a non-polymerized shell form comprising a
polymerizable material. The shell form contains a cavity therein so that
it can be mounted over a dental model of a patient's dental anatomy. A
heated polymerizable material is introduced into the cavity of the shell
form. The shell is then placed over an area of the dental model that will
receive the restoration. The shell and polymerizable material are allowed
to cool so as to form a dimensionally, shape-stable uncured restoration
on the model. The shell and polymerizable material are irradiated with
light so that the shell and polymerizable material cure and form a
hardened restoration. The fully cured restoration is then removed from
the model. The first and second polymerizable materials may comprise
polymerizable acrylic compound and a polymerization system capable of
being activated by light or heat for polymerizing the composition.
Preferably, the polymerizable materials contain filler particulate. The
first and second polymerizable materials may be the same or different
compositions.

[0018] In another embodiment, a dental practitioner can make the dental
restoration in the dental office. The restoration can be made while the
patient is sitting in the dental chair. This method involves dispensing a
heated polymerizable material into a non-polymerized shell form. The same
polymerizable materials as described above can be used in this method.
The practitioner positions the shell containing the polymerizable
material in the mouth of a patient so the material is molded over the
prepared tooth that will receive the restoration. Then, the shell and
polymerizable material are irradiated with light to form a
partially-cured restoration inside of the mouth. After removing the
partially-cured restoration from the tooth, it can be irradiated with
light outside of the mouth to form a fully cured restoration.

[0019] Another chairside method involves positioning the shell containing
the polymerizable material in the mouth of a patient so the material is
molded over the prepared tooth. The material is allowed to cool and
harden to form a shape-stable restoration. The restoration remains
shape-stable even though it is in an uncured condition. The shape-stable
material can be partially-cured by a self (chemical) curing mechanism,
thermal treatment, or irradiation with light. The partially-cured
restoration can be removed and then irradiated with light to form a fully
cured restoration.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The present invention relates to methods of making dental crowns,
bridges, inlays, onlays, veneers, implants, and other dental restorations
using shell forms. In one embodiment, the restoration can be fabricated
indirectly by a dental laboratory and sent to a dentist for placing in
the mouth of a patient. In another version, the dentist can make the
restoration at the patient's chair in the dental office.

[0021] The shell forms of the present invention are made from
polymerizable dental material, which can either be an unfilled resinous
composition or a filled resinous composition, that is, a composition
containing filler particulate. The polymerizable material used in
accordance with this invention comprises a polymerizable acrylic compound
and polymerization initiation system, capable of being activated by light
or heat, for polymerizing the material. Preferably, the polymerizable
composition is a composite material containing filler particulate. By the
term. "composite material" as used herein, it is meant that the material
contains at least a portion of particulate filler. The polymerizable
material and restorations prepared from such materials have certain
properties, the test methods for measuring such properties being
described below.

[0022] The polymerizable dental materials of the invention preferably
include from about 0.1 to about 100 percent by weight of a crystalline
resin and from about 0 to 100 percent by weight of an amorphous
component. When heated, the polymerizable materials soften and are more
flowable and have less crystallinity. The polymerizable materials can
rapidly solidify. Rapid solidification provides the materials with a
combination of flowable and dimensional stability properties, depending
upon the temperature prior to polymerization. Furthermore, in a preferred
embodiment, the polymerizable materials can partially recrystallize
rapidly. This ability to rapidly recrystallize helps densify the
polymeric products and provides the products with flowable and
dimensionally-stable properties, depending upon temperature prior to
polymerization. The polymerizable materials have several different
characteristics, particularly that of: i) flowable dental composites at
elevated temperatures, ii) of packable composites at lower temperatures
as the material cools down; and iii) of wax-like composites at room
temperature and body temperature. The polymerizable dental material
includes a portion of crystals, which melt during polymerization. The
crystalline portion is believed to include crystals of oligomer and/or
crystals of monomer. The volume of the liquid formed by melting the
crystals is greater than the volume of the crystals. This expansion
reduces the shrinkage of the polymerizable dental material caused by
polymerization.

[0023] "Crystallinity" as used herein refers to regularity and order
within a material resulting in a heat of fusion of at least 1.0 J/g at
and below 50° C. "Heat of Fusion" as used herein refers to
enthalpy of fusion as determined by ASTM 793-95. Percent crystallinity is
determined by measuring the heat of fusion using differential scanning
calorimetry according to ASTM test method E 793-95.

[0024] "High strength dental polymeric material" as used herein means a
material having flexural modulus of at least 200,000 psi and flexural
strength of at least 5,000 psi. More preferably, the material has
flexural modulus of at least 300,000 psi and flexural strength of at
least 8,000 psi. Most preferably, the material has flexural modulus of at
least 400,000 psi and flexural strength of at least 12,000 psi. The
flexural strength and flexural modulus properties are measured according
to ASTM D790 (1997).

[0025] "Wax-like" as used herein refers to material which is flowable
(fluid) at and above 40° C., and becomes dimensionally stable
(solidifies, that is, becomes non-fluid) at least at and below 23°
C., within 5 minutes. Thus, wax-like material is flowable when it is at a
temperature of 40° C. and greater, and becomes dimensionally
stable when it is at a temperature of 23° C. and lower. Flowable
wax-like material having a temperature from 100° C. to 40°
C., becomes dimensionally stable within 5 minutes upon cooling by
exposing it to ambient temperature between 37° C. and 0° C.
Flowable wax-like composite paste having a temperature from 100°
C. to 40° C., becomes dimensionally stable within (in order of
increasing preference) 4, 2, 1 or 0.5 minutes upon cooling by exposing it
to ambient temperature between 23° C. and 0° C.

[0028] In addition to the foregoing polymerizable acrylic compounds, the
composition may contain acidic monomers such as dipentaerythritol
pentacrylate phosphoric acid ester (PENTA);
bis[2-(methacryloxyloxy)-ethyl]phosphate; and vinyl compounds such as
styrene, diallyl phthalate, divinyl succinate, divinyl adipate and
divinylphthalate. Diluent polymerizable monomers also may be added to the
composition. For example, hydroxy alkyl methacrylates, ethylene glycol
methacrylates, and diol methacrylates such as tri(ethylene glycol)
dimethacrylate (TEGDMA) may be added to reduce viscosity and make the
composition more suitable for application. A polymerizable acrylic
compound can be used alone in the composition or mixtures of the
compounds can be used. Mixtures of polymerizable monomers and oligomers,
as described in the Examples below, are particularly preferred.

Polymerization System

[0029] A polymerization system can be used in the composition of this
invention, which initiates polymerization (hardening) of the composition
by a light-curable or heat-curable reaction. In one embodiment, a
photoactive agent such as, for example, benzophenone, benzoin and their
derivatives, or alpha-diketones and their derivatives is added to the
composition in order to make it light-curable. A preferred
photopolymerization initiator is camphorquinone (CQ). Photopolymerization
can be initiated by irradiating the composition with blue, visible light
preferably having a wavelength in the range of about 380 to about 500 nm.
A standard dental blue light-curing unit can be used to irradiate the
composition. The camphorquinone (CQ) compounds have a light absorbency
maximum of between about 400 to about 500 nm and generate free radicals
for polymerization when irradiated with light having a wavelength in this
range. Photoinitiators selected from the class of acylphosphine oxides
can also be used. These compounds include, for example, monoacyl
phosphine oxide derivatives, bisacyl phosphine oxide derivatives, and
triacyl phosphine oxide derivatives. For example,
2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (TPO) can be used as the
photopolymerization initiator. In one embodiment, a material referred to
as "ALF" comprising camphorquinone (CQ); butylated hydroxytoluene (BHT);
N,N-dimethylaminoneopentyl acrylate, and methacrylic acid can be used in
the composition.

[0030] In another embodiment, heat-activated polymerization initiators,
such as peroxides, can be added to make the composition heat-curable. The
peroxides generate free radicals to initiate polymerization and hardening
of the composition at elevated temperature. Peroxides such as dibenzoyl
peroxide (BPO), di-p-chlorobenzoyl peroxide, di-2,4-dichlorobenzoyl
peroxide, tertiary butyl peroxybenzoate, methyl ethyl ketone peroxide,
ditertiary butyl peroxide, dicumyl peroxide and cumene hydroperoxide, and
the like can be used.

[0031] In addition to the photoactive and heat activated agents, the
composition may include a polymerization inhibitor such as, for example,
butylated hydroxytoluene (BHT); hydroquinone; hydroquinone monomethyl
ether; benzoquinone; chloranil; phenol; butyl hydroxyanaline (BHT);
tertiary butyl hydroquinone (TBHQ); tocopherol (Vitamin E); and the like.
Preferably, butylated hydroxytoluene (BHT) is used as the polymerization
inhibitor. The polymerization inhibitors act as scavengers to trap free
radicals in the composition and to extend the composition's shelf life.

Fillers

[0032] Conventional filler materials, including reactive and non-reactive
fillers, may be added to the composition. Reactive fillers include metal
oxides and hydroxides, metal salts, and glasses that are acid-reactive.
Such fillers are commonly used in dental ionomer cements. Examples of
metal oxides include, but are not limited to, barium oxide, calcium
oxide, magnesium oxide, and zinc oxide can be used. Examples of metal
salts include, but are not limited to, aluminum acetate, aluminum
chloride, calcium chloride, magnesium chloride, zinc chloride, aluminum
nitrate, barium nitrate, calcium nitrate, magnesium nitrate, and
strontium nitrate. Suitable glasses include, but are not limited to,
borate glasses, phosphate glasses, and fluoroaluminate glasses. The
glasses may or may not have fluoride-releasing properties. The benefits
of using fluoride-releasing glasses are well known. Such materials are
capable of releasing fluoride into the oral cavity over the long term.
Fluoride generally provides added protection against acid attack that can
cause tooth decay. Although, such fluoride-releasing glasses are
generally not used in temporary dental restorations, since such
restorations are intended for short-term use only. Organic particles such
as poly(methyl methacrylate), poly(methyl/ethyl methacrylate),
crosslinked polyacrylates, polyurethanes, polyethylene, polypropylene,
polycarbonates and polyepoxides, and the like also can be used as
fillers.

[0033] A wide variety of non-acid reactive filler materials and
nanoparticles also can be added to the composition. Inorganic fillers,
which can be naturally-occurring or synthetic, can be added. Such
materials include, but are not limited to, silica, titanium dioxide,
zirconia, alumina, iron oxides, silicon nitrides, glasses such as
calcium, lead, lithium, cerium, tin, zirconium, strontium, barium, and
aluminum-based glasses, borosilicate glasses, strontium borosilicate,
barium silicate, lithium silicate, lithium alumina silicate, kaolin,
quartz, and talc. Preferably, the silica is in the form of silanized
fumed silica. A preferred glass filler is silanized barium boron
aluminosilicate.

[0034] The average particle size of the particles comprising the filler
material is normally in the range of about 0.1 to about 10 microns and
more preferably in the range of about 0.1 to about 5 microns. If a fumed
silica filler material is used, the silica particles are preferably
nanometer-sized. Other nano-particles can be used in the composition if
desired. The silica particles and nano-particles preferably have an
average diameter of less than 200 nm. The filler particles can be
surface-treated with a silane compound or other coupling agent to improve
bonding between the particles and resin matrix. Suitable silane compounds
include, but are not limited to,
gamma-methacryloxypropyltrimethoxysilane,
gamma-mercaptopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane,
and combinations thereof.

[0035] In one preferred embodiment, the composition comprises about 5 to
about 15 wt. % TBDMA; about 3 to about 10 wt. % HDIDMA; about 1.5 to
about 5 wt. % HDIDA; about 5 to about 10 wt. % UDMA; about 5 to about 10
wt. % EBPADMA; about 0 to about 0.5 wt. % TPO; about 0.1 to about 1.0 wt.
% ALF and about 50 to about 80 wt. % filler material (silicon
dioxide/glass). In another embodiment, the composition is substantially
free of the ALF activator or TPO activator.

[0036] In yet another preferred embodiment, the composition comprises
about 0 to about 10 wt. % TBDMA; about 3 to about 15 wt % modified
Bis-GMA, about 2 to about 10 wt. % HDIDMA; about 0 to about 5 wt. %
HDIDA; about 0 to about 10 wt. % UDMA; about 0 to about 10 wt.% EBPADMA;
about 0 to about 0.5 wt. % TPO; about 0.1 to about 1.0 wt. % ALF and
about 50 to about 80 wt. % filler material (silicon dioxide/glass).

[0037] These compositions were formulated to match the Refractive Index
(RI) of the fillers used so as to obtain optimum translucency in the
cured compositions. The matched RI of the components enabled the
fabrication of translucent enamel layers of dental restorations and
provided superior esthetics to the dental restorations.

[0038] TBDMA is added to the composition in the form of semi-solid high
molecular weight oligomers. The addition of TBDMA provides the composite
with good toughness and strength, good handling properties and adjusts
the Refractive Index (RI) of the composite material to provide the
desired translucency. HDIDMA and HDIDA are added as solid,
semi-crystalline monomers. The H2O modified HDIDMA and HDIDA also
provides a reduced crystallization time. Modified Bis-GMA, UDMA and
EBPADMA are added as liquids in order to adjust filler load and softness
at the uncured stage and increase the flowability of the composite
material. These components also can further adjust the RI of the cured
composite material, while assisting in decreasing the cure time.
Lucirin-TPO and ALF are photoinitiators that initiate the polymerization
of the monomers and oligomers and provide a relatively short cure time.
Pigments are used to adjust the shade of the composite. The filler
materials added to the composition to provide the composition with
beneficial handling and mechanical properties.

[0039] As described further below, the composite material used in the
method and shell forms of this invention is dimensionally stable when it
is in its uncured state. The composite material, with its
semi-crystalline components as described above, forms a hard, non-sticky
surface layer upon being crystallized. The semi-crystalline components
are partially recrystallizable and help the material to rapidly solidify.
When polymerized, the crystallized phase melts effectively resulting in
volume expansion, which offsets polymerization shrinkage somewhat. The
resulting material has low shrinkage and stress.

[0040] The above-described composition can be used to manufacture shell
forms, which can be used to fabricate dental crowns, bridges, inlays,
onlays, veneers, and other dental restorations. Although the method of
this invention is described primarily below as a method for making a
dental crown, it should be understood that the method can be used to make
any desired dental restoration.

Shell Forms

[0041] The shell forms used in the method of this invention can be made
from the above-described polymerizable materials including polymerizable
composite materials and unfilled resins. The color and shade of the
prefabricated shell is carefully selected. For example, the shell can be
made with a polymerizable material resembling the enamel layer and/or
dentin layer of natural teeth. The enamel layer formulations generally
have higher melting points and provide rigidity during manipulation while
maintaining occlusal and enamel details. On the other hand, the dentin
layer formulations generally have a relatively lower melting points that
impart extended softness and working time. The shell forms can be made
from, among other compositions, the enamel layer formulations, dentin
layer formulations, or combinations thereof. Preferably, the shell form
is made using a combination of the enamel and dentin layer formulations
since they provide excellent esthetics and durability. The enamel and
dentin layers offer superior esthetics with translucency and
polychromatic color graduation of natural teeth. The combined layers
provide fast and natural looking dental restorations. The polymerizable
materials of this invention offer unique uncured shell forms with
convenient handling, unique shape-stability, easy contouring at the
uncured stage, improved strength and wear-resistance and superior
esthetics. The polymerizable materials can be used by dental technicians
and dentists to fabricate various restorations for provisional and long
term applications.

[0042] The making of unique enamel shaded shell forms or multi-chromatic
(both enamel and dentin shaded) shell forms enables the fabrication of
multi-chromatic crowns and bridges with superb esthetics. In addition,
the uncured shells, veneers, crowns, bridges, and implants of this
invention offer unsurpassed advantages over conventional materials and
methods for easy occlusal adjustment. Thus, restorations with ideal
occlusal surfaces and comfortable bites can be made for the patient.

[0043] The polymerizable materials are quickly and easily reshaped, for
example by warming; shaping the materials while warm; and then allowing
the materials to cool to body (37° C.) or room temperature
(23° C.). The cooled polymerizable materials may be worked, for
example, by pressing, packing, molding, shaping, and/or carving. The
worked polymerizable dental materials are then cured.

[0044] The melting point of the shell material is preferably about 0 to
50° C. higher than that of the dentin filling material of this
invention. More preferably, the melting point of the shell material is
about 1 to 30° C. higher and most preferably about 2 to 20°
C. higher than that of the dentin filling material.

Methods

Indirect Dental Laboratory Method

[0045] In one method for making the dental crown, which can be referred to
as an indirect dental laboratory method, the dentist prepares the tooth
that will receive the crown by filing and grinding it to a "core" or
"stump." A high-speed or low-speed handpiece equipped with a diamond bur
is used to grind the tooth. The dentist takes a final impression of the
patient's entire dental anatomy including the prepared tooth. Lastly, a
conventional provisional crown can be mounted over the prepared tooth
structure to protect it while the more permanent crown is being made in
accordance with this invention.

[0046] The hardened impression is sent to a dental laboratory that will
fabricate the crown. The dental technician, at the laboratory, prepares a
cast (or model) by pouring dental plaster or stone into the hardened
impression. This results in a finished plaster model having a shaped
surface closely matching the patient's complete dental anatomy including
the prepared tooth that will receive the crown. In other cases, the
dentist will prepare the finished plaster models and send them directly
to the laboratory.

[0047] The laboratory technician selects a prefabricated shell form made
from the above-described polymerizable material. The color and shade of
the prefabricated shell is carefully selected. The shell is then trimmed
and adjusted so that it fits over a targeted area of the plaster model
that will receive the crown. The shell form is in an uncured condition at
this point so it can be trimmed, carved, stretched, molded or pressed
easily to achieve a desired shape. The shell form is trimmed so that it
can be tightly seated on the model and good margins, interproximal
contacts, and occlusion can be achieved.

[0048] Next, the dental practitioner or laboratory technician dispenses a
dental polymerizable material into the cavity of the shell form. The
injected polymerizable material can be the same polymerizable material
used to construct the shell, or the respective materials can be different
as mentioned above. Preferably, a composite material containing filler
particulate is used to fill the shell cavity. If different materials are
used, they should still be compatible so they can cross-polymerize and
bond with each other. The shell form containing the composite material is
then seated and shaped over the area of the model requiring the crown. It
is recognized that more than a single layer of the shaded composite
material can be injected into the shell form. Preferably, the composite
material is heated to a temperature generally above 40° C. and
preferably to a temperature in the range of about 50° C. to about
100° C. If the temperature is too low, the material will not flow
sufficiently. On the other hand, if the temperature is too high, the
material will take a substantially long time to cool (solidify). Care
should be taken that the correct amount of composite material is placed
into the shell form. If a sufficient amount of composite material is not
introduced, gaps will form in the resulting crown, and there will be
occlusion problems. On the other hand, if too much composite material is
introduced, the occlusion of the crown may be too high. This can occur
even though the highly flowable nature of the heated composite material
allows excess material to squeeze out easily. The shade of the composite
material is carefully selected so that it matches the color of the
patient's natural teeth.

[0049] Alternatively, in some cases, the shell form can be seated directly
on the plaster model without first filling the shell form with composite
material. The laboratory technician selects a shell form having the
desired shade and shape. The shell form is in an uncured condition at
this point so it can be trimmed, carved, stretched, molded or pressed
easily to form an optimum crown structure. The technician can easily mold
and shape the shell form over the area (prepared tooth) of the model
requiring the crown.

[0050] In the case of making a short-span dental bridge, the technician
may select shell form(s) to fit in edentulous areas on the dental model.
The selected and prepared shell form(s) for pontic tooth (or teeth) in
edentulous areas can be filled with selected shade composites or resins
as prescribed by dentists so as to match the patient's natural dentition.
The non-polymerized shell forms can be joined easily by melting the
surface of the shell forms or adding selected shade composites or resins
to join them together as needed.

[0051] The technician presses the filled pontic shell form on the surface
of edentulous areas on the dental model to form the pontic. The filled
material is allowed to harden. Then, the excess material is removed from
the model. The resulting pontic(s) is ready to be joined with the crown
form(s) using the composite material of this invention, which are
polymerized together to form a hardened integral bridge. Alternatively,
reinforcing metal, fiber, or ceramic bars or wires can be conveniently
imbedded in the polymerizable material to enhance its strength and load
bearing capability.

[0052] As discussed above, if the dentist has prepared the tooth for
receiving the crown in the office visit and taken an impression of the
prepared tooth, a dental model of the patient's dental anatomy including
the crown-prepped tooth is fabricated. The dental laboratory may make
this model, or the dentists may make this model at their office and send
it to the laboratory. An oxygen barrier coating or other separating agent
is applied to the surface of the model.

[0053] As described above, in the laboratory process for making a crown,
once the shell form has been filled sufficiently with the composite
material, it is placed over the area of the dental model that includes
the tooth receiving the crown. Once seated, the shell form and composite
material are allowed to set for approximately one to three minutes to
form a shape-stable, uncured crown structure. Although the shell form and
composite material are uncured at this point, they are dimensionally
stable and remain substantially fixed in place. The shell forms and
polymerizable materials have wax-like characteristics, good viscosity at
elevated temperature, and favorable handling properties. The materials do
not slump or substantially change shape. Contoured and molded to form a
crown on the targeted area of the dental model, the shell forms and
composite material do not expand or shrink substantially from that site.

[0054] If necessary, additional composite material or resin can be added
to the external surface of the shell form to touch-up the crown as it is
seated on the model. Any excess, composite material on the model also
should be removed. The excess composite material can be removed from the
model using a knife or other sharp instrument. Then, a thin layer of a
visible light curing (VLC) sealer is applied to the surface of the crown.
Now, the model, which is seated with the outer shell form and composite
material in a crown shape, is placed in a light-curing oven and
irradiated with curing light and heated in accordance with a
pre-determined curing cycle. The curing time will depend upon many
different factors including the light-curing oven used. In general, the
materials of this invention completely set and harden in the range of
about one (1) to about fifteen (15) minutes. The outer shell form and
composite material are polymerized and bond together to form a hardened
integral crown structure

[0055] After the cured dental crown and supporting model are removed from
the oven, the assembly is cooled. Then, the crown is removed from the
model using fingers, a crown remover, or other suitable instrument. The
crown is finished and polished using conventional techniques as needed.
The crown can be polished using buffing wheels. Aluminum oxide can be
used to steam-clean the interior surface of the dental crown for
subsequent effective bonding to reline or cement material at the
dentist's office. If needed, the crown also can be mechanically polished
using buffing wheels and abrasives. Lastly, if the practitioner or
technician wishes, a VLC sealant which provides a stain-resistant and
glossy surface finish may be applied to the surface of the crown and the
crown may be cured again in a light-curing oven.

[0056] The dental laboratory sends the finished crown back to the dentist.
Once the dentist receives the crown, he or she can prepare the tooth that
will receive the crown, if this has not already been done, by filing the
tooth structure to a core or stump as described above. Then, the crown is
affixed to the prepared_tooth in the mouth of the patient using a
suitable reline material and dental cement. Conventional dental cements,
as are known in the dental field, may be used in this step. In cases
where a temporary crown has been mounted over the tooth structure, it is
first removed and then the crown of this invention is affixed to the
tooth using dental cement.

[0057] In another embodiment, a substructure such as, for example, a metal
coping can be used in the construction of the crown, bridge, or other
restoration. The underlying substructure helps support the composite
material used to make the restoration. Thus, the polymerizable composite
material forms the visible portion of the crown and is bonded to the
underlying substructure. Additional mechanical retention may be
introduced to improve and maintain the integrity of bonding between the
substructure and polymerizable composite material.

[0058] The strength and toughness of the crown can be enhanced by using a
metal coping or other supporting substructure. Cast metals, alloys,
ceramo-metal materials, high strength ceramics and fiber-reinforced
composites can be used as copings or substructures for the restorations.
The high strength ceramics include but not limited to alumina, zirconia,
mullitc, titanium oxide, magnesium oxide, SIALON and their mixtures.
Metals and alloys and their mixtures, such as Nobel alloys,
palladium-based alloys, cobalt-based alloys, nickel-based alloys, pure
titanium and alloys, gold-based metal-ceramic alloys, nickel chromium
alloys, etc. can be used as copings or substructures. Possible
reinforcing fibers include glass, carbon, graphite, polyaramid, high
density polyethylene, alumina, mixture thereof, as well as other fibers
known in the art. It is understood that any suitable substructure can be
used to make the crown, bridge, or other restoration in accordance with
this invention. For example, ceramic (metal-free) substructures such as
CERCON systems (Dentsply) and fiber-reinforced copings can be used as
well as metal copings.

Dental Practitioner's Chairside Method

[0059] Following this method, a dental practitioner first prepares the
patient's tooth that will receive the crown. Then the dental practitioner
selects a shell form having the appropriate shade and shape for fitting
over the prepared tooth in the patient's mouth. The shell form can be
trimmed and adjusted as needed.

[0060] Next, the dental practitioner dispenses the dental composite
material of this invention into the shell form and then immediately seats
and shapes the shell over the prepared tooth. The composite material is
heated. As discussed above, it is important that the correct amount of
composite material be placed into the shell form. The shade of the
composite material is also carefully selected and customized so that it
matches the color of the patient's natural teeth. The dentist may wish to
inject multiple layers of the shaded composite material into the shell
form.

[0061] After filling the shell form with the composite material, the shell
is inserted into the patient's mouth. It is positioned in the mouth in
such a way that the composite material is molded and shaped over the
prepared tooth that will receive the restoration. As the shell form is
fitted in the mouth, excess composite material is allowed to escape
around the margins and adjacent teeth. A single shell form is used to
make the dental crown in this embodiment. Similarly, the dental
practitioner can prepare bridges, inlays, onlays, veneers, implants, and
other dental restorations. In cases where multiple shells are involved,
the shells can be joined together by adding flowable composite, resin or
adhesive, or by melting or adding the warmed polymerizable material. The
shell forms are polymerized together to form a hardened integral bridge.

[0062] Alternatively, the dentist can prepare a model and work outside of
the mouth. In this case, the dentist takes an impression of the prepared
tooth (teeth) using conventional impression material. A model including a
core or stump tooth structure is then made by pouring or injecting a low
viscosity and suitably rigid die material, such as die silicone, plaster,
dental stone, or the like into the hardened impression. Then, the shell
form which contains the composite material as described above can be
fitted over the dental model and a crown can be prepared. Following this
method, the dentist can work extraorally to prepare the crown.

[0063] Moreover, in some cases, the shell form can be used directly on the
prepared tooth in the patient's mouth without first filling the shell
with composite material. The dental practitioner or laboratory technician
selects a shell form having the desired shade and shape. The practitioner
or technician can easily mold and shape the shell form over the area
(prepared tooth) of the model requiring the crown. The shell form is in
an uncured condition at this point so it can be trimmed, carved,
stretched, molded or pressed easily to form an optimum crown structure in
the patient's mouth. The shell form can be shaped and contoured so that
it will have good margins, interproximal contacts, and occlusion.

[0064] Turning back to the chairside method described above, the shell
containing the heated composite material is inserted into the patient's
mouth and the material is allowed to cool and form a dimensionally
stable, uncured crown structure. The uncured crown structure is then
removed from the mouth. If needed, the dentist trims excess composite
material away from the margins and adjacent teeth. Next, the uncured,
shaped crown structure is placed back inside of the mouth so that the
crown is positioned over the prepared tooth structure. The patient can
bite down on the crown so that margins, contacts, and occlusion can be
checked by the practitioner and adjusted accordingly. The fitted crown is
then removed from the mouth.

[0065] Next, the crown is irradiated with light so that it cures and forms
a fully hardened crown product. Preferably, the crown structure is first
injected with a rapid self-curing silicone (die silicone or fast set
plaster) to lock the crown shape in place and then it is placed'in a
light-curing unit. The injected die silicone or fast set plaster helps
minimize potential shape distortion of the crown during the curing
process. (The hardened die silicone or plaster is subsequently removed
from the crown structure after the curing process.) Suitable light-curing
ovens for curing the crown structure are available from Dentsply
including, for example, the Eclipse® processing unit, Enterra®
visible light-curing (VLC) unit, and Triad® 2000 VLC unit.
Alternatively, a standard handheld dental curing light can be used.
Suitable handheld light units include halogen, plasma arc (PAC) and
light-emitting diode (LED) dental curing lights include, for example,
those sold under the brand names: QHL75® Lite (Dentsply),
Spectrum® 800 curing unit (Dentsply), Optilux® 401 (Kerr),
Sapphire (DenMat), SmartLite iQ2® (Dentsply); Elipar® (3M Espe);
and L. E. Demetron II® (Kerr).

[0066] The crown can be finished with burs and polished using customary
finishing techniques as needed. In addition, a VLC sealant, which
provides a stain-resistant and glossy surface finish may be applied to
the crown. The sealer helps provide the crown with improved esthetics and
reduces polishing time.

[0067] The finished crown is now ready to be temporary or permanently
affixed to the tooth. Conventional temporary or permanent cements, as
known in the dental field, may be used in this step. In a second
embodiment of this method, the composite material cools and forms a
stable, uncured crown structure inside of the mouth. The shape-stable
uncured crown structure remains in the mouth. The dentist can then trim
excess composite material away from the margins of the crown and adjacent
teeth. As the patient bites down on the crown, the margins, contacts, and
occlusion can be checked by the practitioner and adjusted accordingly.
Next, the shaped crown structure is partially cured in the mouth using a
handheld dental curing light. Suitable curing lights for performing this
partial curing step are described above. The partially cured crown is
then removed from the mouth. It may be finished with a bur as needed.
Optional, a die silicone may be injected into this partially cured crown
to form a supporting model for optimal dimensional stability before final
cure. In addition, a sealant, which provides a stain-resistant and glossy
surface finish may be applied to the crown. A dental curing light or
light-curing oven may be used to fully cure the crown structure.

[0068] A third version of this method is similar to the method described
above, except there is no partial curing step. The composite material is
completely cured outside of the mouth. Particularly, this method involves
first cooling the composite material to form a stable, uncured crown
structure within the mouth. The practitioner can check the crown fit and
make any needed adjustments. Then, the shaped crown structure is removed,
injected with die silicone to from a supporting model if desired and
fully cure the structure by exposing it to light radiation outside of the
mouth using dental curing lights or ovens.

[0069] Following a fourth method also is similar to the first method.
First, the composite material is allowed to form a dimensionally stable,
uncured crown structure and then it is removed from the mouth. After
excess composite material is trimmed away from the margins and adjacent
teeth, the uncured, shaped crown structure is placed back inside of the
mouth so that the crown is positioned over the prepared tooth structure.
The adjusted and fitted crown is then partially cured if the dentist
wishes to perform this step. Then, the partially-cured crown can be
removed and finished with burs and polished to its final desired shape.
After applying a sealant to the crown's surface, it is ready to be fully
cured and hardened. Optionally, a die silicone may be injected into this
partially cured crown to form a supporting model.

[0070] In a fifth method, which is similar to the above-described third
method, a self-cure composite or resinous material can be injected into
the shell form and then immediately seated and shaped over the prepared
tooth. Once the self-cure composite or resin has partially-polymerized,
excess material is removed. Then, the partially-cured crown is removed
from the prepared tooth so that the injected filling material can be
additionally cured. The practitioner can then place the crown back onto
the prepared tooth in the patient's mouth and check the crown fit and
make any needed adjustments. Then, the shaped crown structure is removed,
injected with die silicone to form a supporting model if desired, and
fully-cured by exposing the structure to light radiation outside of the
mouth using dental curing lights or ovens.

[0071] One advantageous property of the composite material and shell form
used in this invention is that they can be shaped and molded to form
stable, uncured crown structures. The molded, shape-stable crown can be
partially light-cured inside of the mouth. This partial-curing step
normally occurs after the margins, interproximal contacts, and occlusion
have been checked and adjusted accordingly. The above-mentioned dental
curing lights may be used to partially cure the material. Then, the
partially-cured crown is removed from the mouth and finished with burs
and polishers to its final desired shape. After applying a sealant to the
crown's surface, it is ready to be fully cured and hardened. The crown
may be placed in a standard light-curing oven, as mentioned above, and
fully cured via light irradiation.

[0072] The uncured, shape-stable restorations prepared according to the
methods of this invention have advantages over conventional materials
with respect to occlusal adjustment, comfort, and fitting. For example,
one problem with conventional materials occurs when the impression matrix
or shell is seated over the prepared teeth. At this point, excess resin
is forced into the gingival margins of the prepared tooth and it covers
adjacent teeth and gum tissue. Upon curing, the excess resin forms a
flash. This flashing must be removed and the cervical finish line of the
restoration must be accurately adapted at the gingival margins to avoid
initiating marginal gingivitis. Removing this cured flashing requires the
use of finishing burs. It is very difficult to remove the cured flashing
without damaging the cervical finish line or gingival tissue at the
gingival margin. Furthermore, flashing below the gum line cannot be
effectively removed without the risk of nicking or otherwise damaging
adjacent teeth.

[0073] The disadvantages with conventional methods and restoration
materials are overcome by the present invention. As discussed above, the
dimensionally shape-stable uncured restorative can be molded, removed,
carved or flowed as needed and excess flashing can be controlled.
Furthermore, since the polymerizable materials and shell forms are
shape-stable when they are in an uncured condition, even if excess
material flow or flashing occurs, it can be removed easily without
damaging the restoration.

[0074] The dental restorations produced by each of the methods of this
invention have excellent properties and can be used as provisional or
long-term restorations. Preferably, the restorations produced by this
invention are high strength dental polymeric materials having a flexural
modulus of at least 400,000 psi and a flexural strength of at least 5,000
psi. More preferably, the high strength dental polymeric materials have a
flexural modulus of at least 1,000,000 psi and a flexural strength of at
least 10,000 psi. In addition, the restorations can be custom-made so
they accurately reproduce the polychromatic color graduation of natural
teeth. A dental practitioner can use the dental restoration as a
provisional expecting that it will remain in the patient's mouth for a
time period of about 1 to about 12 months. Moreover, if there is a need,
the dental practitioner can use the restoration long-term, expecting that
it will remain in the patient's mouth for a period of time longer than
about 12 months. The restorations have high mechanical strength, pleasing
aesthetics, a hard and smooth surface finish, and good margins and
contacts making them ideal products for protecting the dental health of a
patient.

[0075] This invention meets the needs of the dental profession for quick
and accurate ways to fabricate provisional and long-term crowns, bridges,
and other restorations. Temporary, semi-permanent and permanent crowns,
bridges and multi-tooth crowns, and other restorations can be fabricated
conveniently in accordance with the methods of this invention. Several
advantages are provided by these methods. For example, only a single
shell form needs to be used, since it can be adjusted to fit several
differently shaped teeth. The uncured shell forms are highly adjustable
by pressing, molding, melting, and carving. The tooth colored dentin
resins or composite materials can be dispensed easily to fill the shell
form, once they are heated in conventional ovens, warm water baths, or by
hot air guns, syringes or compule warmers, or other heating elements and
methods. The finished restorations provide good fit and comfort without
substantial drilling and trimming being required. In addition, the
restorations are durable enough for provisional and long-term use.

[0076] The present invention is further illustrated by the following
examples, but these examples should not be construed as limiting the
scope of the invention.

EXAMPLES

[0077] In the following examples, unless otherwise indicated, all parts
and percentages are by weight.

Example 1

Preparation of Oligomer

[0078] A reactor was charged with 1176 grams of
trimethyl-1,6-diisocyanatohexane (5.59 mol) and 1064 grams of bisphenol A
propoxylate (3.09 mol) under dry nitrogen flow and heated to about
65° C. under positive nitrogen pressure. To this reaction mixture,
10 drops of catalyst dibutyltin dilaurate were added. The temperature of
the reaction mixture was maintained between 65° C. and 140°
C. for about 70 minutes and followed by additional 10 drops of catalyst
dibutyltin dilaurate. A viscous paste-like isocyanate end-capped
intermediate product was formed and stirred for 100 minutes. To this
intermediate product, 662 grams (5.09 mol) of 2-hydroxyethyl methacrylate
and 7.0 grams of BHT as an inhibitor were added over a period of 70
minutes while the reaction temperature was maintained between 68°
C. and 90° C. After about five hours stirring under 70° C.,
the heat was turned off, and oligomer was collected from the reactor as
semi-translucent flexible solid and stored in a dry atmosphere.

Example 2

Preparation of Monomer

[0079] A reaction flask was charged with 700 grams of
1,6-diisocyanatohexane and heated to about 70° C. under a positive
nitrogen pressure. To this reactor were added 1027 grams of
2-hydroxyethyl methacrylate, 0.75 gram of catalyst dibutyltin dilaurate
and 4.5 grams of butylated hydroxy toluene (BHT). The addition was slow
and under dry nitrogen flow over a period of two hours. The temperature
of the reaction mixture was maintained between 70° C. and
90° C. for another two hours and followed by the addition of 8.5
grams of purified water. One hour later, the reaction product was
discharged as clear liquid into plastic containers and cooled to form a
white solid and stored in a dry atmosphere.

Example 3

Preparation of Monomer

[0080] A reaction flask was charged with 168 grams of
1,6-diisocyanatohexane and heated to about 70° C. under a positive
nitrogen pressure. To this reactor were added 228 grams of 2-hydroxyethyl
acrylate, 0.12 gram of catalyst dibutyltin dilaurate and 0.86 grams of
butylated hydroxy toluene (BHT). The addition was slow and under dry
nitrogen flow over a period of two hours. The temperature of the reaction
mixture was maintained between 70° C. and 85° C. for
another three hours and followed by the addition of 0.9 grams of purified
water. One hour later, the reaction product was discharged as clear
liquid into plastic containers and cooled to form a white solid and
stored in a dry atmosphere.

Example 4

Preparation of Monomer

[0081] A reaction flask was charged with 151.25 grams of octadecyl
isocyanate and heated to about 70° C. under a positive nitrogen
pressure. To this reactor were added 125.3 grams of caprolactone
2-(methacryloyloxy)ethyl ester, 0.12 gram of catalyst dibutyltin
dilaurate and 0.58 grams of butylated hydroxy toluene (BHT). The addition
was slow and under dry nitrogen flow over a period of two hours. The
temperature of the reaction mixture was maintained between 70° C.
and 85° C. for another 2.5 hours, the reaction product was
discharged as clear liquid into plastic containers and cooled to form a
semi-opaque solid and stored in a dry atmosphere.

Examples 5A and 5B

[0082] Tables 1 show the components of the compositions of Examples 5A and
5B. The compositions of Examples 5A and 5B were prepared by mixing the
components shown in Table 1 at 85° C.

[0083] Table 2 shows the physical properties of the selected compositions
from Examples 5A and 5B, which have been polymerized by light cure in
Triad light unit. The commercially available products, Integrity®,
Triad® Provisional (sold by Dentsply International) and Jet acrylic
(sold by Lang Dental) were prepared and cured according to manufacturing
instructions.

[0084] Volume loss (cubic mm at 400,000 cycles), was used as a measure of
the wear-resistance of the polymerized compositions. A three body cyclic
abrasion wear machine (Leinfelder method in vitro/University of Alabama)
was used to determine volume loss. Samples were cured in a Triad®
light curing unit for 10 minutes.

[0086] Flexural Strength and Flexural Modulus of the polymerized
compositions of this invention and the commercially available materials
were measured by using three-point bend test on Instron bending unit
according to ISO 10477. Polymerizable materials of this invention were
cured in a Triad® light curing unit for 5 minutes for the Example 5A
samples and 10 minutes for the Example 5B samples.

Example 6

Preparation of Monomer

[0087] A 200 mL reaction flask was charged with 14.0 grams of
1,12-diisocyanatododecane and heated to about 87° C. in a oil bath
under a dry air pressure. To this flask were added 16.2 grams of
2-hydroxylpropyl methacrylate, 0.05 gram of catalyst dibutyltin
dilaurate, and 0.11 grams of butylated hydroxy toluene (BHT). The
addition was completed over a period of 34 minutes. The temperature of
the reaction mixture was maintained around 90° C. for another 2.7
hours, the reaction product was discharged as a slightly cloudy liquid
into a beaker and cooled to form a white solid and stored in a dry
atmosphere. This monomer can be used to compound shape-stable
polymerizable materials in accordance with this invention.

[0088] Example 7A

Crown Tooth Shell

[0089] Multiple crown tooth shells were formed by compressive molding a
disk of the product of Example 5A in a two-part mold. The composition of
Example 5A was preheated in a 60° C. oven before being compressed.
Optionally, a thin elastic releasing film was used to enable the easy
release from the molds, which may also be a part of the package.

Example 7B Crown Tooth Shell

[0090] Multiple various crown tooth shells were prepared by pouring or
injecting the melted product of Example 5B in two and three part molds,
which formed shape stable shells upon cooling. The composition of Example
5B was melted and degassed in a 95° C. vacuum oven before being
poured or injected.

Example 7C

Crown Tooth Shell

[0091] Multiple crown tooth shells were formed by stamping a disk of the
product of Example 5D in a two-part mold. The composition of Example 5D
was preheated in a 55° C. oven before being pressed. Optionally, a
thin elastic releasing film was used to enable the easy release from the
molds, which may also be a part of package.

Example 7D

Crown Tooth Shell

[0092] Multiple crown tooth shells were formed by compressive molding a
piece of the product of Example 5A in a three-part mold. The composition
of Example 5A was dispensed from a heated syringe before being
compressed.

Example 7E

Crown Tooth Shell

[0093] Multiple various crown tooth shells were prepared by pouring or
injecting the melted product of Example 5B in silicon mold cavities and
then immediately placed in a matched silicone mold (part of this mold
part was fitted inside the cavities of shells) to form shape stable
shells upon cooling. The composition of Example 5B was melted and
degassed in a 95° C. vacuum oven before being poured or injected.
Optionally, the silicone mold(s) become(s) a part of the package.

Example 7F

Crown Tooth Shell

[0094] Multiple various two-layered crown tooth shells were prepared
according to following steps. First, the melted product of Example 5B was
poured or injected into silicon mold cavities and then immediately placed
in a first matched silicone mold to form shape-stable enamel forms upon
cooling. After the first matched silicone mold was removed from the
silicone mold cavities to leave enamel forms remaining in the cavities,
the melted product of Example 5A was poured or injected into silicon mold
cavities and then immediately placed in a second matched silicone mold to
form shape-stable shell forms upon cooling (part of this mold part was
fitted inside the cavity of shell). This process formed shells with two
layers of different shades. The compositions of Example 5A and 5B were
melted and degassed in a 95° C. vacuum oven before being poured or
injected. Optionally, the silicone mold(s) become(s) a part of the
package.

Example 8

[0095] Tables 3 and 4 show the components of the compositions of Examples
8A through 8H. The compositions of Examples 8A through 8H were prepared
by mixing and degassing the components shown in Tables 3 and 4 at
90° C.

[0096] Multiple crown tooth shells were formed by compress molding a disk
of the product of Example 8A in a two-part mold. The composition of
Example 8A was preheated in a 60° C. oven before being compressed.
Optionally, a thin elastic releasing film was used to enable the easy
release from the molds, which may also be a part of the package.

Example 9B

Crown Tooth Shell

[0097] Multiple various crown tooth shells were prepared by pouring or
injecting the melted product of Example 8C in two and three-part molds,
which formed shape-stable shells upon cooling. The composition of Example
8C was heated to 70° C. before being poured or injected.

Example 9C

Crown Tooth Shell

[0098] Multiple crown tooth shells were formed by stamping a disk of the
warmed product of Example 8A in a two-part mold. The composition of
Example 8A was preheated in a 50° C. oven before being pressed.
Optionally, a thin elastic releasing film was used to enable the easy
release from the molds, which may also be a part of the package.

Example 9D

Crown Tooth Shell

[0099] Multiple crown tooth shells were formed by applying a thin layer of
the heated product of Example 8C to form enamel layers in two or
three-part mold. After the enamel layers were solidified, the heated
product of Example 8D was added and compress molded in a three-part mold.
The composition of Example 8D was dispensed from a heated syringe before
being compressed. Multiple shells with two layers of different shades
were made.

Example 9E

Crown Tooth Shell

[0100] Multiple various crown tooth shells were prepared by pouring or
injecting the melted product of Example 8H, 8A or 8C in silicon mold
cavities and then immediately placed in a matched silicone mold (part of
this mold part was fitted inside the cavities of shells) to form
shape-stable shells upon cooling. The compositions of Example 8H, 8A, or
8C were melted and degassed in a 85° C. vacuum oven before being
poured or injected. Optionally, the silicone mold(s) become(s) a part of
the package.

Example 9F

Crown Tooth Shell

[0101] Multiple various two-layered crown tooth shells were prepared
according to following steps. First, the melted product of Example 8H,
8A, or 8C was poured or injected into silicon mold cavities and then
immediately placed in a first matched silicone mold to form shape-stable
enamel forms upon cooling. After the first matched silicone mold was
removed from the silicone mold cavities to leave enamel forms remaining
in the cavities, the melted product of Example 8E, 8B, or 8D was poured
or injected into the silicon mold cavities and then immediately placed in
a second matched silicone mold to form shape-stable shell forms upon
cooling (part of this mold part was fitted inside the cavity of the
shell). This process formed shells with two layers of different shades.
The compositions of Example 8E, 8B, 8D, 8H, 8A, or 8C were melted and
degassed in a 85° C. vacuum oven before being poured or injected.
Optionally, the silicone mold(s) become(s) a part of package.

Example 9G

Crown Tooth Shell

[0102] Multiple various crown tooth shells were prepared by injecting the
melted product of Example 8G in silicon coated mold cavities and then
immediately placing it in a matched silicone coated mold (part of this
mold part was fitted inside the cavities of the shells) to form
shape-stable shells upon cooling. The composition of Example 8G was
melted and degassed in a 85° C. vacuum oven before being injected
into the mold cavities.

Example 9H

Crown Tooth Shell

[0103] Multiple various two layered crown tooth shells were prepared
according to following steps. First, the melted product of Example 8G was
injected into a two-part mold cavities and then immediately placed in a
first matched silicone coated mold (part of this mold part was fitted
inside the cavities of the enamel layers) to form shape-stable enamel
forms upon cooling. After the first matched silicone coated mold was
removed from the mold cavities to leave remaining enamel forms in the
cavities, the melted product of Example 8F was injected into the mold
cavities and then immediately placed in a second matched silicone coated
mold. This formed shape-stable shell forms upon cooling (part of this
mold part was fitted inside the cavities of the shells). This process
formed shells with two layers of different shades. The compositions of
Example 8F and 8G were melted and degassed in a 85° C. vacuum oven
before being poured or injected.

Example 10

Chairside Crown Mounted Using Dental Cement

[0104] A dentist selected and prepared a suitable composite shell form
made from Example 9B to match the shade and size of the tooth requiring
the crown. After the tooth was prepped, the shell form was adjusted and
the polymerizable composite of Example 8D was injected into shell form
and seated on the prepped tooth to form a crown. After excess materials
were removed, the uncrured crown was occluded, contoured and adjusted
easily (since it was shape-stable in the uncured state), and then removed
from the tooth and trimmed. A fast set rigid silicone (optional) was
injected into crown and sealer was applied. The crown structure was then
cured in an Enterra® light-curing unit (Dentsply) for 5 minutes to
form a final crown, which was subsequently finished and polished. The
finished crown was ready to be cemented on the crown-prepped tooth in the
patient's mouth.

Example 11

Chairside Crown Mounted Using Dental Cement

[0105] A dentist selected and prepared a suitable composite shell form
made from Example 9F of the polymerizable composite 8H to match the shade
and size of the tooth requiring the crown. After the tooth was prepped,
the shell form was adjusted and the polymerizable composite of Example 8E
was injected into shell form and seated on the prepped tooth to form a
crown. After excess materials were removed, this uncured crown was
occluded, contoured, adjusted and cured with a handheld light for 5
seconds. It was then removed from the tooth and trimmed. A fast set rigid
silicone (optional) was injected into the crown and sealer was applied.
The crown structure was then cured in an Enterra® light-curing unit
(Dentsply) for 5 minutes to form a final crown, which was subsequently
finished and polished. The finished crown was ready to be cemented on the
crown-prepped tooth in the patient's mouth.

Example 12

Chairside Crown Mounted Using Dental Cement

[0106] A dentist selected and prepared a suitable composite shell form
made from Example 9E to match the shade and size of the tooth requiring
the crown. After the tooth was prepped and a thin layer of flexible
spacer was applied and formed, TPH®3 Flow (Dentsply) was injected
into the shell form and seated on the prepped tooth to form a crown.
After excess materials were removed, this uncured crown was occluded,
contoured, adjusted and cured using a handheld light for 5 seconds. The
crown was then removed from the tooth and trimmed. A fast set rigid
silicone (optional) was injected into the crown and sealer was applied.
The crown structure was cured in a Triad® light-curing unit
(Dentsply) for 10 minutes to form final crown. The crown was then removed
from the light unit and shaped and contoured as needed. A thin layer of a
visible light-curing sealer (optional) was applied to the surface of the
crown and the crown was cured for about two minutes. The crown was
subsequently finished and polished as needed. The finished crown was
ready to be cemented on the crown-prepped tooth in the patient's mouth.

Example 13

Chairside Crown Mounted Using Dental Cement

[0107] A dentist selected and prepared a suitable shell form made from
Example 7F to match the shade and size of the tooth requiring the crown.
After the tooth was prepped, Integrity® (Dentsply) was injected into
the shell form and seated on the prepped tooth to form a crown. After
excess materials were removed, the partially-cured crown was occluded,
contoured, adjusted and then removed from the tooth and trimmed.
(Alternatively, the partially-cured crown can be removed first and then
placed back on the tooth to occlude, adjust and contour.) The crown
structure is then removed from the mouth and trimmed. A fast set rigid
silicone (optional) was injected into the crown and sealer was applied.
The crown structure was cured in a Triad® light-curing unit
(Dentsply) for 10 minutes to form a final crown. The crown was then
removed from the light unit and shaped and contoured as needed. A thin
layer of a visible light curing sealer (optional) was applied to the
surface of the crown and the crown was cured for about two minutes. The
crown was subsequently finished and polished as needed. The finished
crown was ready to be cement on the crown-prepped tooth in the patient's
mouth.

Example 14

Chairside Crown Mounted Using Dental Cement

[0108] A dentist selected and prepared a suitable composite shell form
made from Example 9H to match the shade and size of the tooth requiring
the crown. After the tooth was prepped, the shell form was trimmed,
adjusted, seated, molded and pressed on the prepped tooth to form a
crown. After excess materials were removed, this uncured crown was
occluded, contoured, adjusted and light-cured using a handheld light for
5 seconds. The crown was then removed, trimmed, finished and polished. A
fast set rigid silicone (optional) was injected into the crown and sealer
was applied. The crown structure was cured in a Triad® light-curing
unit (Dentsply) for 10 minutes to form a final crown, which was
subsequently finished and polished. The finished crown was ready to be
cemented on the crown-prepped tooth in the patient's mouth.

Example 15

Chairside Bridge Mounted Using Dental Cement

[0109] A dentist selected and prepared three suitable shell forms made
from Example 7A to match the shade and size of teeth requiring the crowns
and pontic (bridge). After the teeth were prepped, Integrity®
(Dentsply) was injected into shell forms and seated on the prepped teeth
and pontic space to form multiple crown units. A flowable composite
TPH®3 Flow was injected to join the shells together and the structure
was tack-cured with a handheld light to form a bridge. After excess
materials were removed, the partially-cured bridge was, occluded,
contoured, adjusted and then removed from the teeth and trimmed.
(Alternatively, the partially-cured bridge can be removed first and then
placed back on the teeth to occlude, adjust and contour). The bridge
structure was then removed from the mouth and trimmed. A fast set rigid
silicone (optional) was injected into the bridge and sealer was applied.
The bridge structure was cured in an Enterra® light-curing unit
(Dentsply) for 5 minutes and flip-cured for additional 1.5 minutes to
form a final bridge. The bridge was then trimmed, shaped and contoured as
needed. A thin layer of a visible light-curing sealer (optional) was
applied to the surface of the bridge and the bridge was cured for about
two minutes. The bridge was subsequently finished and polished as needed.
The bridge was ready to be cemented on the crown-prepped teeth in the
patient's mouth.

Example 16

Chairside Bridge Mounted Using Dental Cement

[0110] A dentist selected and prepared three suitable shell forms made
from Example 9H to match the shade and size of the teeth requiring the
crowns and pontic (bridge). After the teeth were prepped, the
polymerizable composite material 8E was injected into shell forms and
seated on the prepped teeth and pontic space to form multiple crown
units. Heated composite 8E and heated tool were used to join the shells
together and cool them to form the bridge. After excess materials were
removed, this uncured bridge was occluded, contoured, adjusted and cured
using a handheld light for 15 seconds. The partially-cured bridge was
then removed from the mouth and trimmed and shaped. A fast set rigid
silicone was injected into bridge and sealer was applied. The bridge
structure was cured in an Enterra® light-curing unit (Dentsply) for 5
minutes and flip-cured for additional 1.5 minutes to form final bridge.
The bridge was then trimmed, shaped and contoured as needed. The bridge
was subsequently finished and polished as needed. The finished bridge was
ready to be cemented on the crown-prepped teeth in the patient's mouth.

Example 17

Laboratory Fabricated Crown Mounted Using Dental Cement

[0111] First, a laboratory technician prepared the plaster model having a
shaped surface closely matching the patient's complete dental anatomy
including the tooth that was to receive the crown. Then, he selected and
prepared a suitable shell form according to the dentist's recommendation
to match the shade and size of the tooth requiring the crown. A shell
form made from Example 7A was used. After the tooth for was prepped on
the model, Jet Acrylic (Long Dental) was prepared and applied into the
shell form and seated on the prepped tooth on the model to form a crown.
After excess materials were removed, the crown was occluded, contoured
and adjusted and then cured in a Triad® light-curing unit (Dentsply)
for 10 minutes to form a final crown. Afterwards, a thin layer of a
visible light-curing sealer (optional) was applied to the surface of the
crown. The crown was then removed from the model and shaped and contoured
as needed. An additional thin layer of a visible light curing sealer was
applied to the surface of the crown and the crown was cured for about two
minutes. The crown was subsequently finished and polished as needed. The
labratory fabricated crown was ready to send to the dentist to reline and
cement on the crown-prepped tooth in the patient's mouth.

Example 18

Laboratory Fabricated Crown Mounted Using Dental Cement

[0112] First, a laboratory technician prepared the plaster model having a
shaped surface closely matching the patient's complete dental anatomy
including the prepared tooth that was to receive the crown. Then, he
selected and prepared a suitable shell form according to the dentist's
recommendation to match the shade and size of the prepared tooth. After a
shell form made from Example 9H was selected, it was trimmed, seated and
adjusted on the prepped tooth on the model. The heated polymerizable
composite material of Example 8E was then injected into shell form and
seated on the prepped tooth on the model. After excess materials were
removed, this uncured crown was occluded, contoured and adjusted and then
cured in a Triad® light-curing unit (Dentsply) for 10 minutes to form
a final crown, which was subsequently finished and polished. A thin layer
of a visible light-curing sealer (optional) was applied to the surface of
the crown prior to curing or after curing (in case of applying sealer
after cure, additional 2 minutes of curing time in the Triad® 2000
light-curing unit is needed). The crown was ready to be sent to the
dentist to cement on the crown-prepped tooth in the patient's mouth.

Example 19

Laboratory Fabricated Bridge Mounted Using Dental Cement

[0113] First, a laboratory technician prepared the plaster model having a
shaped surface closely matching the patient's complete dental anatomy
including the teeth that was to receive the bridge. Then he selected and
prepared suitable shell forms according to the dentist's recommendation
to match the shade and size of the teeth requiring the bridge. Shell
forms made from Example 9D were used. After the teeth were prepped on the
model, the shell forms were trimmed, seated and adjusted on the prepped
teeth on the model. The heated polymerizable composite material of
Example 8D was injected into the shell forms and seated on the prepped
teeth and pontic space to form multiple crown units. An electric spatula
and additional composite of Example 8D were used to join shells together
and cooled to form a bridge. After excess materials were removed, the
bridge was occluded, contoured and adjusted easily since it was
shape-stable and in the uncured state. A thin layer of a visible light
curing sealer might be applied to the surface of the bridge, which was
cured in an Enterra® light-curing unit (Dentsply) for 5 minutes and
flip-cured for additional 1.5 minutes to form the final bridge. The
bridge was then trimmed, shaped and contoured as needed. A thin layer of
a visible light curing sealer (optional) was applied to the surface of
this cured bridge and the bridge was cured for an additional two minutes.
The bridge was subsequently finished and polished as needed. The bridge
was ready to be sent to the dentist to reline and cement on the
crown-prepped teeth in the patient's mouth. .

Example 20

Laboratory Fabricated Bridge Mounted Using Dental Cement

[0114] First, a laboratory technician prepared the plaster model having a
shaped surface closely matching the patient's complete dental anatomy
including the prepared teeth that was to receive the bridge. Then, he
selected and prepared suitable shells form according to the dentist's
recommendation to match the shade and size of teeth requiring the bridge.
Shell forms made from Example 9F were used, which were trimmed, seated
and adjusted on the prepped teeth on the model. A ceramic reinforced bar
was also prepared to reinforce the bridge. The heated polymerizable
composite material of Example 8D was injected into the shell forms. The
ceramic reinforced bar was imbedded in the shell forms and joined
together using an electric spatula and seated on prepped teeth and pontic
space to form multiple crown units. An electric spatula and additional
composite material from Example 8D were used to completely join the
shells together and cool them to form a bridge. After excess materials
were removed, the bridge was occluded, contoured and adjusted. A thin
layer of a visible light curing sealer might be applied to the surface of
the bridge, which was cured in an Enterra® light-curing unit
(Dentsply) for 5 minutes and flip-cured for an additional 1.5 minutes to
form final bridge. The bridge was then trimmed, shaped and contoured as
needed. A thin layer of a visible light curing sealer (optional) was
applied to the surface of this cured bridge and the bridge was cured for
an additional two minutes. The bridge was subsequently finished and
polished as needed. The bridge was ready to send to the dentist to cement
on the crown-prepped teeth in the patient's mouth.

[0115] It should be understood that while the present invention has been
described in considerable detail with respect to certain specific
embodiments thereof, it should not be considered limited to such
embodiments but may be used in other ways without departure from the
spirit of the invention and the scope of the appended claims.